How to control the SYS_CLKREQ?

challenger002

Intellectual 690 points

I am using the Windows Embedded Compact 7 on the AM3517EVM.

I want to stop the external clock while suspending the system.

What should I do to control the SYS_CLKREQ?

Best regards,

Daisuke

over 13 years ago

0 Adeneo Embedded support team over 13 years ago

Mastermind 9310 points

The SYS_CLKREQ pin is automatically controlled by the PRCM when the CPU needs to be fed with an external clock. The PRCM should also release this pin to high impedance when the CPU is in RETENTION mode. Have you verified if that mechanism works?

0 challenger002 over 13 years ago in reply to Adeneo Embedded support team

Intellectual 690 points

Thank you for a reply.

No, I did not verify it.

To tell the truth, I received this question from our customer.

Our customer wants to stop the external clock while suspending the windows system.

Is this operation supported by device driver included in SDK for Windows?
Otherwise what must they do?

Do I have to check a version of SDK which they use?

Best regards,

Daisuke

0 Adeneo Embedded support team over 13 years ago in reply to challenger002

Mastermind 9310 points

This should be done automatically so there is no other way than using the latest BSP on the board, putting the board to suspend mode and probe the clock signal with a scope to check it's off.

0 challenger002 over 13 years ago in reply to Adeneo Embedded support team

Intellectual 690 points

Thank you for a reply.

It is necessary for our customer to get an answer immediately.

We have AM3517EXP, but cannot confirm your method immediately because we have never operated Windows on the board and our customer requires to return from suspending by touching the touch panel but AM3517EXP does not have it.

What is the method that we get an answer immediately?
Is it to ask Logic PD, Inc. about the latest BSP?

Best regards,

Daisuke

0 challenger002 over 13 years ago in reply to challenger002

Intellectual 690 points

Does anyone know whether this operation (i.e. the windows system stops the external clock by controlling the SYS_CLKREQ while suspending and is returned from suspending by touching the touch panel) is supported by BSP?

Best regards,

Daisuke

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How to control the SYS_CLKREQ?